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// Copyright (C) 2016 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-integer-indexed-exotic-objects-defineownproperty-p-desc
description: Consistent canonicalization of NaN values
info: |
This test does not compare the actual byte values, instead it simply checks that
the value is some valid NaN encoding.
---
[[DefineOwnProperty]] ( P, Desc)
...
3. If Type(P) is String, then
...
b. If numericIndex is not undefined, then
...
xi. If Desc has a [[Value]] field, then
1. Let value be Desc.[[Value]].
2. Return ? IntegerIndexedElementSet(O, intIndex, value).
...
#sec-integerindexedelementset
IntegerIndexedElementSet ( O, index, value )
...
15. Perform SetValueInBuffer(buffer, indexedPosition, elementType, numValue).
...
#sec-setvalueinbuffer
SetValueInBuffer ( arrayBuffer, byteIndex, type, value [ ,
isLittleEndian ] )
8. Let rawBytes be NumberToRawBytes(type, value, isLittleEndian).
#sec-numbertorawbytes
NumberToRawBytes( type, value, isLittleEndian )
1. If type is "Float32", then
a. Set rawBytes to a List containing the 4 bytes that are the result
of converting value to IEEE 754-2008 binary32 format using “Round to
nearest, ties to even” rounding mode. If isLittleEndian is false, the
bytes are arranged in big endian order. Otherwise, the bytes are
arranged in little endian order. If value is NaN, rawValue may be set
to any implementation chosen IEEE 754-2008 binary64 format Not-a-Number
encoding. An implementation must always choose either the same encoding
for each implementation distinguishable *NaN* value, or an
implementation-defined canonical value.
2. Else, if type is "Float64", then
a. Set _rawBytes_ to a List containing the 8 bytes that are the IEEE
754-2008 binary64 format encoding of _value_. If _isLittleEndian_ is
*false*, the bytes are arranged in big endian order. Otherwise,
the bytes are arranged in little endian order. If _value_ is *NaN*,
_rawValue_ may be set to any implementation chosen IEEE 754-2008
binary64 format Not-a-Number encoding. An implementation must
always choose either the same encoding for each implementation
distinguishable *NaN* value, or an implementation-defined
canonical value.
...
#sec-isnan-number
NOTE: A reliable way for ECMAScript code to test if a value X is a NaN is
an expression of the form X !== X. The result will be true if and only
if X is a NaN.
includes: [nans.js, testTypedArray.js]
features: [TypedArray]
---*/
testWithTypedArrayConstructors(function(FA) {
var precision = FA === Float32Array ? "single" : "double";
var samples = new FA(1);
var controls, idx, aNaN;
for (idx = 0; idx < NaNs.length; ++idx) {
aNaN = NaNs[idx];
controls = new FA([aNaN, aNaN, aNaN]);
Object.defineProperty(samples, "0", { value: aNaN });
for (var i = 0; i < samples.length; i++) {
var sample = samples[i];
var control = controls[i];
assert(
samples[i] !== samples[i],
`samples (index=${idx}) produces a valid NaN (${precision} precision)`
);
assert(
controls[i] !== controls[i],
`controls (index=${idx}) produces a valid NaN (${precision} precision)`
);
}
}
}, [Float32Array, Float64Array]);
reportCompare(0, 0);
|
